The Collaborative International Dictionary of English v.0.48:
gallowstree \gallowstree\ n. same as gallows. Syn: gallows, gibbet, gallows tree, gallow tree. [WordNet 1.5]WordNet (r) 3.0 (2006):
gallows-tree n 1: alternative terms for gallows [syn: gallows tree, gallows-tree, gibbet, gallous]